/Engine/Plugins/Runtime/MassGameplay/Source/MassLOD/Public/MassLODSubsystem.h
Returns PlayerController pointer from the viewer handle
[APlayerController](API\Runtime\Engine\GameFramework\APlayerController) * GetPlayerControllerFromViewerHandle ( const [FMassViewerHandle](API\Plugins\MassLOD\FMassViewerHandle) & ViewerHandle ) const